Means for preventing reradiation in antenne



8, 1 31- R. A. WEAGANT ET AL 1,835,126

MEANS FOR PREVENTING RERADIATION IN ANTENNFE] Filed Jan. 22, 1925 Patented Dec; 8, I931 mm. wEAeANr, no'UeLiisroiv, NEW smmm GEORGEA. soMERsALo, or a s: CITY, nnwfannsrmnssrenons o m1 ronnsc mnro COMPANY, or JERSEY crrY,

, NEW JERSEY, a conronnrlonor DELAWARE FOR PREVENTING RERAiDIATION I 1\T ANTENNE Application 'filed January 22, 1925. Serial No; 3,980.

The object of this invention is the provision of new, simple and inexpensive, but positive, means for preventing oscillations generated by aradio receiving setfrom being reradiatedby the antenna. a g A further object of the invention is to pro vide meansfor afiording-two or more input circuits to an electrical instrumentality, e, g., a l threeeelectrode thermionic vacuum tube or, audion, which can be independe itly severally adjusted without any interaction or mutual efl'ect therebetween,

The invention consists substantially the construction, combination, locationand rel ative arrangement ofpa-rts, as well, as in the V.

circuit I arrangement employed in connection therewith, all as willbe; more fully hereinafter set forth, as shown by the accompanying drawings andfinally pointed out inthe appended claims i v 3 Re'ferringto thedrawings- "Fig. 1 is a diagrammatic,illustrationvof a simple oneat'ube regenerative detector ,with our invention appliedthereto;

Figs. 2 and 3 show modified arrangements embodying our invention.

Thesam lpart is designated by the same reference character wherever it ,occurs The disadvantage, annoyance and disturbance incident to the employment of 1 radio receiving -circuits whichggenerate oscillations and, ,thr ,11gh the receiving. antenna, radiate the j-sameyare so well: recognized that even the advantagesito be derived from throughont the several views.

the amplification properties of a regenerative circuit are, fast being 'sacrificed because the near proximity of ,another ant nna has impossible,Ior-, if not impossible, far from passed prohibiting the use of regenerative 1 :circnits, for this reason;

a Other circuits, however, 1 are p of the strictly regenerative type especially the 7 a tive receiver as efficiently as any other number.

multitube circuits, setup oscillations which 7 may be equally disturbing, due tofvarious types or" couplingbetw'een the respective circuits of the respective tubes, whereby, while a regenerative connection is not. employed, a regenerative .eliectis secured. 1

7 his among the special purposes of our present invention to provide an exceedingly simple arrangement or unitfiior the pre ven j tlOIl Of OSCIllE-tlODiS set up in.thefreceiving circuits or equipment from being radiated from the receiving antenna.

,jlhe nature of the inventioniislfsuch that may be utilizedas a unit, or unitary construction, and employed as an' 'accessory to; existing receivlng sets. .The commercial advantageof this will be readily appreciated inasmuch as but atslight' expense-the accessory may be added to existing equipment.

Furthermore, the invention is of such a nature that it can be applied to any receiv ing set, irrespective of the number of tubes it employs or the type of circuits employed therewith. In other words, the invention may be employed with a singletuberegenerit may be with Einally, while the invention, as; above stated, maybe embodied ina very easily connected accessory to'e'xisting' radio sets,'i t may be incorporated in the constructiol fof-vnew sets, irrespective of size or circuit, at mini mum additional expense and practically no alterationot design; "In thefco-pending application of Roy A. Weaga'nt, (one of the inventors hereinabove ji'dentified), Serial No. 752,835, filed Novemthereo Y lt'isrof L rs ,:We ,v known th t a radiating antenna located adjacent to oriin such a disturbing effectthereon as to render the reception ,of'broadcast news and Vmusic her 29,1924, forRadio-signaling systems, is

pling, etc., wherein the phase relationoi the circuits is"'controlled to "effecta balance be tween the circuits" and thus prevent the generationjof oscillationsj f; V Referring tothe drawing's,-r;eerence character 1 designates anordinarytype of thermionic, vacuum tube, including :the filament electrode 2 and the plate electrode 3, w-ith the gridielectrode' 4 interposed therebetween.

The grid electrode 4 is connected to the filament electrode through a network to which it is connected at the point 5, one branch including the inductance 6 shunted by variable capacity 7 forming the tuned input or oscillation circuit, the opposite terminals of which are connected to the point 8 of the netues 18, 19, 9 and 10 in any of the well-known ways, so as to effect a VVheatstone bridge or similar type of network, the nodal points 17 V and 8 are totally unaffected by oscillations in any of the circuits of the vacuum tube 1. \Vhile we have shown the objects of the 1nvention for the purpose of illustrat on as secured by the employment of capacities for the electrical elements of the grid or network, we wish it to be understood that any other type of electrical elements, such as nductances, resistances, or combinations of 1nductances, resistances and capacities, may be employed. 7

It will be seen, therefore, that the balanced effect is totally unafiected by any type of circuit employed with the antenna, and this is true wholly independently of the number of tubes employed. It is, of course, possible to put a variable inductance 20, such as a variometer or any other type of inductance, across the nodal points 17 and 8 of the network without in any way affecting the input tuning 6, 7, or without in any way being affected by the input tuning.

It will be readily appreciated that this affords a simple and, as we believe, the only possible way of separate tuning with any regenerative circuit employing a single tube, without disturbing reactions. If desired, the variable inductance 20 may be placed in series with the network, either between the network and ground or between the network and the aerial. To illustrate this feature Fig. 3 is shown with the variable inductance 20 connected between the antenna and the nodal point 17.

While in Fig. 1 we have shown the invention as applied to a radio receiving set, we do not desire to be limited or restricted in this respect as the invention forms an ideal form of coupling between tubes so that it is possible to independently tune the input and output circuits without any reactions; i. e.,

permit maximum transference of energy with selectivity and absence of reactive effects.

Having in mind that the input circuit of any thermionic vacuum tube would be connected between the points 5 and 8, it will be apparent that the entire assembly forms an exceedingly simple but nevertheless positive preventer of radiation in the antenna of oscillations generated in the receiving circuit, and at the same time provides an accessory to eX- isting sets irrespective of circuit arrangement.

One very important feature of our present invention is the fact that by the use of the radiation preventer it is possible to utilize a single aerial for any number of receiving sets, and the practicability and commercial value thereof will be readily apparent. Particularly in congested districts, such as in large cities, where a number of people reside in apartments, instead of necessitating independent aerials for each apartment, as heretofore, a single aerial for each building, for example, may be provided, with attachment thereto by as many of the dwellers in the building as desired.

It will be seen from the foregoing that it is possible by means of our invention to employ two or more input circuits to any electrical instrumentality or system, such, for eX- ample, as an audion system, and that variation of the electrical constants of one of these input circuits can be effected without in any way afiecting the others in any manner whatsoever. The great value of being thus able to employ a plurality of input circuits independently tunable or adjustable, as well as the advantages that can be obtained thereby, will be readily apparent to those skilled in the art.

Having now set forth the objects and nature of our invention, and having shown and described structures embodying the principles thereof and one application thereof, to which, however, as pointed out, we do not desire to be limited or restricted, what we claim as new and useful, of our own invention, and desire to secure by Letters Patent, is

1. The combination with a three electrode vacuum tube having a controlling system and a controlled system of a balanced capacity network having two sets of nodal points, an input circuit connected across one set of nodal points, a tuned circuit connected across the other set of nodal points, an inductance for across one set of nodal points, a variably tuned circuit connected across the other set of nodal points, means for inductively conpling the controlled circuit of said electron discharge device with said tunedcircuit, and connections including the. controlling circuit of said electron discharge device and one arm of said network.

3. The combination according to claim 2- V in which the controlling and controlled circuits are coupled through said inductance and said tuned circuit to ative feed back. I

4. The combination according to claim 2 in which each arm of the network consists substantially entirely of a capacity.

In testimony whereof we have hereunto set our hands on this l7th day of January,

A. D. 1925. V a ROY A. WEAGANT. GEORGE A. SOMERSALO.

provlde a regener- 

